Metamaterial Interfaces for Quantum Electronics

The quest to design materials with tailored properties is a driving force for new scientific and technological horizons and is critical for addressing the grand challenges of humanity. Our proposal introduces an innovative concept in condensed matter and materials science: heterostructures built upon the fusion of 2D van der Waals materials and freestanding transition metal oxides (TMOs), forming a new compound metamaterial where the interface itself plays a crucial and active role in the properties and functionality. Our strategy is threefold. First, by incorporating a 2D layer between two TMO crystals to prevent ionic-covalent bonding and disorder, we can stack the TMOs with a continuous, free choice of twist angle. This will dial in interfacial superstructures called moiré lattices, which impose profound changes in their physical properties. Second, the moiré lattices will ‘imprint’ ferroic orders in the interfacial 2DL, which then act as a spacer, lubricating layer, and sensing layer in one. Moiré engineering has so far been reserved for van der Waals materials, and with METRIQS, we seamlessly merge TMOs with van der Waals materials, creating a highly versatile hybrid platform, where the interaction strength, strain, and dislocation networks can be controlled. Moiré metamaterials are used to study valleytronics and correlated states, control skyrmions, realise spin-charge conversion devices, and control the nucleation of chiral molecules. Our most ambitious endeavour unfolds in the third phase, where we are committed to revolutionising material synthesis by design. This will be achieved through interface manipulation, employing a combination of static and dynamic techniques, including strain, light, and electric/magnetic fields, in conjunction with the precise control of the bilayer twisted oxide as a tuning knob. This project unites two separate scientific communities and material families, in a team with highly complementary skills, knowledge, and resources.